Polarized FTIR Spectroscopy in Conjunction with In Situ H/D Exchange Reveals the Orientation of Protein Internal Carboxylic Acids

摘要

The seven alpha-helical membrane protein bacteriorhodopsin (bR) is a light-driven proton pump in Halobacterium salinarum with the chromophore retinal bound via a protonated Schiff base (PSB) to a lysine (Lys216) inside the protein.The absorption of a photon initiates a cyclic reaction involving different intermediates (ground state (BR) - J<->K<->L<->M<->N<->O-> BR).